Valid Monday June 27, 2016 to Friday July 08, 2016
US Hazards Outlook
NWS Climate Prediction Center College Park MD
EDT June 24 2016Synopsis
: At the beginning of the Outlook
period, a cold front is predicted over the Upper Mississippi Valley/Upper Great
Lakes region. This reinforcing shot of cooler, drier air is expected to advance
eastward and southward during the ensuing few days. By the middle of next week,
the front is forecast to extend southward from a low pressure center near Maine
to the Carolinas, gradually curving westward and northwestward across the Gulf
Coast states, and the southern and central Plains, before stalling. This front
is expected to play some role in nearly all of the hazards noted on the map
east of the Continental Divide. Weak low pressure at the surface is anticipated
over the Gulf of Alaska and northern mainland Alaska during the 3 to 7 day
Detailed Summary For Monday June 27 - Friday July 01:
- Heavy rain across portions of South
Dakota and Nebraska, Mon-Tue, June 27-28.
- Heavy rain for northern New England, Mon-Tue, June 27-28.
- Heavy rain across lower portions of the Missouri River Valley, Wed-Thu,
- Much above-normal temperatures from northern and central portions of the
Intermountain Region eastward to near the Idaho/Wyoming border, with a southern
extension across the Central Valley of California, Mon-Fri, June 27-July 1.
- Excessive heat across southern and eastern Texas, most of the Lower
Mississippi Valley, Alabama, Georgia, and the western Florida Panhandle,
Mon-Tue, June 27-28.
- Excessive heat across the lower elevations of the desert Southwest,
Mon-Fri, June 27-July 1.
- Slight risk of much above-normal temperatures across most of California and
the Great Basin, much of the northern and central Rockies, and the northern
Great Plains, Sat-Wed, July 2-6.
- Moderate risk of much above-normal temperatures for eastern portions of
both Washington and Oregon, Idaho, and most of Montana, Sat-Sun, July 2-3.
- Flooding is occurring or imminent for portions of the Trinity River in far
eastern Texas, Mon-Wed, June 27-29.
- Severe Drought across the Central Great Basin, much of California, far
southern Arizona, the Northern High Plains, the Tennessee Valley, the southern
Appalachians, and Hawaii.
A reinforcing shot of
cooler, drier air is predicted to move across much of the central and eastern
CONUS during this period. By the middle of next week, the leading edge of this
cooler air mass is forecast to approach the East Coast, with the southern
portion of this air mass reaching the deep South before stalling. From here,
the cold front is predicted to stretch northwestward across the southern and
central Plains. During this period, three areas of heavy rain (generally 1-2
inches, locally greater amounts possible in thunderstorm activity) are
anticipated, in relation to the movement of this cold front. The first area of
heavy rain is predicted across central portions of Nebraska and adjacent South
Dakota (June 27-28), with the second area being the lower Missouri River Valley
(June 29-30). The third area of predicted heavy rain is over northern New
England, from June 27-28. Though isolated to scattered thunderstorms are
expected to accompany the cold front as it progresses across the eastern and
southern CONUS, no larger-scale, organized areas of severe weather are
delineated on the map at this time.
Excessive heat (daily maximum heat index values predicted to be in excess
of 105 degrees F) is a concern across much of the Gulf Coast region and Lower
Mississippi Valley from June 27-28, associated with the expected presence of
the subtropical ridge, and the forecasted approach of the cold front noted
earlier. Excessive heat is also projected for the lower elevations of the
desert Southwest during the 3-7 day period, where heat index values may exceed
110 degrees F. From much of the northern and central Intermountain region
eastward to near the Idaho/Wyoming border, including a southwestern extension
into the Central Valley of California, temperatures are favored to be much
above-normal (by 12-16 degrees) from June 27-July 1, in association with an
amplifying ridge anticipated over the West.
The high-based thunderstorms that have recently affected parts of the
Southwest are consistent with the early stages of typical Monsoon evolution. As
the lower atmosphere becomes increasingly moist, rain is gradually able to
reach the ground, and increase in intensity. The latest GFS and ECMWF
deterministic model runs predict increasing amounts of precipitation in Arizona
and New Mexico, resulting from the predicted availability of deeper moisture.
The next stage in typical monsoonal evolution normally involves even deeper
moisture moving into the Southwest, often associated with a Gulf surge or a
backdoor cold front, and the ensuing development of heavy rainfall.
Weak areas of low surface pressure are predicted to be over the Gulf of
Alaska, and the northern mainland of Alaska. No hazards are expected at this
For Saturday July 02 - Friday July 08:
The Probabilistic Extremes Outlook
(PEO) tool favors a slight risk of much above-normal temperatures for most of
California and the Great Basin, much of the northern and central Rockies, and
the northern Great Plains, July 2-6. A moderate risk of much above-normal
temperatures is indicated for eastern portions of both Washington and Oregon,
Idaho, and most of Montana, July 2-3. These slight and moderate risk areas
depict where maximum temperature values are expected to exceed the 85th
percentile of the climatological temperature distribution.
According to the U.S. Drought Monitor (USDM), valid on June 21, severe, or
greater intensity, drought covers 4.24 percent of the U.S. Drought Monitor
areas (including Alaska, Hawaii, and Puerto Rico), up slightly from 4.00
percent on June 14.
Forecaster: Anthony Artusa
Click here to see a display of the GFS Ensemble Forecasts
Please consult local NWS Forecast Offices for short range forecasts and region-specific information.